Sewing machine



May 17, 1 21. 629,139

E. B. AL LE N SEWING MACHINE Fil ed Sept. 26 1925 4 Sheets-Sheet l iwmuzssgs, *B K k 9, A ORNEYI May 17 1927.

E. Bf ALLEN SEWING MACHINE Filed Sept. 26 1925 4 Sheets-Sheet 2 20 Duff INVENTOR WITNESSES, BY

y 175 1927' E. B; ALLEYN SEWING MACHINE Filed Sept. 26 1925 4 Sheets-Sheet 5 INVENTOR ATTORNEY wimaygs May 17, 1927.

E. B. ALLEN SEWING MACHINE F iled Sept, 26 1925 4 Sheets-sheaf 4x U \mw;

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Patented May 17, 1927.

UNITED STATES PATENT oF c EDWARD B. ALLEN, or NEWTOWN, CONNECTICUT, ASSIGNOR 'ro THE-SINGER M NU-- FACTURING COMPANY, or ELIZABETH,4-1\TEW JERSEY,. A CORPORATION or NEW JERSEY.

Application filed September 26, 1925.- Serial No. 58,778.

This invention relates to sewing machines of the type having a laterally vibrating needle-and adapted to sew a group of stitches and then come to rest; an'automatic buttonh-ole sewing machine being an example of the type in question. The invention has for anobject to provide a machine of this type having a simplified and improved mechanism for vibrating the needle as well as for periodically changingthe amplitude of vibration of the needle, as in barring one or both ends of a buttonho-le, which mechanism will operate quietly and smoothly and withcertainty and uniformity at high speed and which is under positive control at all times.

Machines of the type in questionembody stitch-forming mechanism and a work-holder with feeding mechanism including a feedwheel andconnections for relatively'moving the stitch-forming mechanism and workholder to place the stitches in the desired order in their grouped formation. In the present embodiment of the improvement the feed-wheel is driven through a train of gears, the initial member of such train carrying a star-wheel with which mesh twodiametrically opposed pins carried by a gear mem ber driven from themain or needle-bar op erating shaft. This pin and star-wheel drive for the feed-wheel imparts to the latter a positive as distinguished from a-frictlonpawl driven step-by-step rotary motion, with periods of dwell during which the needle passes into and out of the work in the forma tion of stitches. In the present instance, the needle-bar is mounted in a swinging gate, as

usual, butsuch gate is vibrated by a pitman connection with a rotary crank driven from the feed-wheel actuating mechanism and hence through the pin-and-star-wheel drive. Thus the needlebar carrying gate is crankdriven instead of cam-driven and is posi tively tied to the feed wheel and parts moved thereby, such as the work-holder, and is held stationary withsuch parts, or worksholder,

{while the needle passes into and out of the work. Positively. acting cam means turning with the feed-wheel operate automatically through suitable connections to shift'or increase the eccentricity of the rotary crank and amplify the vibrations of the needle, as when sewingthe barring stitches of a buttonhole. fying mechanism in question is of such a nature that it may be made light in weight needle-bar.

The cam-actuated vibration-ampli- SEWING MACHINE.

so as to operate efficiently and respondquickly at high speed. The rotary needle-bar vibrating crank is under control-at all times during its shift to a position of increased eccentricity and hence the position of the needle-bar gate driven by such crank is fully under controlduring such shift.

By actuating the needle-bar vibrating mechanism from the intermittent 'feed wheel drive, the dwells produced by the feed-wheel drive can also be communicated to the needlebar guide or gate. A rotary crank-drive can thus be used to advantage, instead of the usual cam-driven arrangements, for'vibrating the needle-bar, by timing the crankdrive relative to the feed-wheel drive so that the dwells produced by the latter occur when the crank 'is in its dead-center or dwell-producing. positions. Thus 'the dwells of the needle-bar guide or gate are practically the sum of the crank-produced dwells (due' to the crank rounding itsdead-center positions) plus the dwells produced by the intermit tent feed-wheel drive.

In the accompanying drawings, Fig. '1 is a side elevation, partly in section, of a buttonhole sewing machine embodying the invention. Fig. 2 is a bottom plan view of the machine.- Fig, 3 is a top plan view of the bracket-arm of the machine. Fig. 4 is a transverse verticalsection through the machine on the line 4'4, Fig. 1. Fig. 5 is a section on the line 5-5, Fig.4. Fig. 6 is a detail view of an element. of Fig. 4. Fig. 7 is a 'plan view of the cam which controls the amplitude of vibration of the needle-bar. .Fig. 8 is a plan view. of the variable crank mechanism which vibrates the Fig. 9 is a section on the line 99, Fig. 8, and Fig. 10 is a disassembled perspective view of certain parts shown in Figs. 8-and 9.

For the purposes of the present disclosure. the invention is described as embodied in an automatic straight buttonhole sewing machine constructed substantially in accord ance with the disclosures of the. patent to E. B. Allen, No. 1,559,529, issued November 3, 1925, and the copending application 'of A. R. W00d, Serial No. 27,627, filed May 4-, 1925. The machine has theusual bed" 1, standard 2-, overhanging arm 3 and head 4. The stitch-forming mechanism comprises the reciprocating-and laterally vibrating needle-bar 5 carryin'gthe eye-pointedneedle 6. The needle-bar is journaled in the swinging gate 7 which is mounted on the pivot pins 8 and derives its vibrato'ry movement from the main sewing shaft 9. The gate 7 may be connected by means of the link 10 to the slotted arm 11 which is fulcrumed at 12 on the bracket-arm 3 and is "connected by the link 13 to the crank-pin 14 mounted on the radially movable slide 15 carried by the rotary guide-head 16 coaxial with the vertical shaft 17'. The guidehead 16 receives semi-rotationalimpulses through the train of gears 18 from the inter- .inediate feed-actuating shaft 19 which carries the star-wheel 20 with which mesh the pins 21., Fig. 3, carried by the hub of the bevel gear 22 mounted on the bearing pin 23 and receiving its motion front the bevel pinion 24 carried by the sewing shaft 9. The gear 22 is driven at half the s eed of the shaft 9 and the gearing 18 is of such. ratio.

that the guide head 16 is given a semi-rotation for each impulse of th star-Wheel 20 received from one of the .pins 21. The

' needle-bar is reciprocated by means of the usual crank 25 andlink connection 26 with the sewing shaft 9.

The Shaft 17. is hollow and slidably rerod 27 having a taper ceives a vertical pointed upper extremity 28- constituting a cam-portion which, when pro'ected upward 1y, engages a transverse e ge-portion or shoulder 29 carried by the slide 15 and shifts such slide to'increase the eccentricity of the 1 crank-pin 14 and thus increase the ampli-' tude of vibration of the needle. The guidehead 16 is equipped with s rings 30 which act against shoulders 30, ig. 10, on the slide 15 to restore it to'init-ial position when the vertical snde-rod 27 is. permitted to descend. A stop 15', Fig. 5, secured to one end ,of the slide 15 isiadapted' to engage one end of the guide-head 1.6 and limit the motion of said slide in one direction.

The vertical slide-rod 27 hasfixed to its lower end the lateral pin 31 which is em-- braced andheld against turning about the axis of the rod 17 by the slotted fixed iguide 32, Fig. .6, which is, secured to the ame of the machine. The pin- 31 is also embraced by the forked forward end of the actuating lever 33 which is fulcrumed 'at 34 on the 1 bracket-arm 3 and has a cam-follower block 35 resting on the upper fiat surface ofthe cam-wheel "36. The cam-wheel 36 is fixed to the same shaft 37 as the main feed-wheel 38 which shifts the work-holder. Secured to the upper surface of .the cam-wheel 36' are the raised blocks 39-which enga e the,

block 35 and liftthe lever-'33 and r0 27. to shift the slide '15 and increase theamplitude of vibration of the needle-bar. the present machine, the cam-blocks 39 are arranged to increase the vibrations of the needle for.

barring bothendsof a straight buttonhole.

' 51. The longitudinal 57 .in the feed-wheel 38.

The vertical rod 27 within the shaft 17 is positively and forcibly lifted by the cam members 39 on the cam-wheel 36 and, furthermore, is light in Weight and, adapted to effectively control the amplitude of vibration of the needle under high-speed operating conditions. The needle-gate 7 is connected at all times to the crank 14, the degree of eccentricity of which is under control at all periods of the cycle of operation of the machine. The provision for driving. the needle-bar vibrating mechanism from the positively or pin-and-star-wheel gear driven feeding mechanism insures coordination at all times between the movements of the work-holder and the vibrating needle and simplifies the machine by making use of a single intermittent drive mechanism (the pin-and-star-wheel drive) for bothmoving the feed-wheel intermittently and vibrating the needle. I

' In the formation of stitches the needle6 cooperates with the usual shuttle (not mounted to slide lengthwise of the machine bed in the cross-slide-pl'ate 52 which slides crosswise of the machine bed in the ways. 53, v53, Fig. 1. The longitudinal slide-plate slide-plate 47 is is actuated by means of the usual link 54,

,l 'ig. 2, and lever 55 havin a follower 56 entering the longitudinal feed cam-groove The cross-slideplate is actuated by the lever 58 which is fulcrumed at 59 on the bed 1 and has a .follower 60 entering the lateral-feed cam,- groove 61 in the feed-wheel. The shaft 37 carrying the feed-wheel 38 and cam-wheel 36 vis driven by means of a train of gears 62, Fig. 4, from'the shaft 19.

The period. f action of the stitch-forming mechanism-f is controlled .by the usual stop-motion device comprising the tight andloose pulleys 63, 64, the belt-shipper 65 and the tilting stop-motion lever 66 carrying plunger 67 2 The particular machine chosen for disclosure of an embodiment of the invention is:

equipped with a control shaft 68 which is disposed transversely-of the machine bed and 1s actuated from a constantly running power-driven pulley 69 through a suitable partial rotation clutch mechanism including the vertically 'movablespring-pressed stoping of the present improvement.

a driven disk 70, Fig. 1, carrying two angularly spaced radially slidable clutch-dogs -71. This mechanism is fully disclosed in the Allen patent, previously referred to and a detailed description thereof is not believed to be necessary to an understandi It wil sulfice to explain that this shaft is automatically given a partial rotation prior to the starting of the stitch-formingmechanism and a second partial'rotatlon after the stitchforming mechanism has come to rest. The

first partial rotation of the shaft 68 serves to close the work-clamp and start the stitchforming mechanism, and the second partial rotation of such shaft is conveniently made use of to operate the button-hole and threadcutting mechanisms and to open the Workclamp. I v

Havingv thus set forth the nature of the invention, What I claim herein is 1. In a group-stitching machine, a reciprocating needle, a needle-gate, a crank-shaft, acrank carried by said shaft, a pitman connection between said crank and gate for viby the sewing shaft for imparting "step-b step rotary motion to the feed-wheel, said I crank bein connected to receive semi-rotational impu sesfrom said pln-and-star-wheel' drive. Y v

2. A group-stitching machine having, in

' combination, a sewing shaft, an intermediate shaft, 21 pm-and-star-wheel driving connection between said sewing and intermediate shafts for imparting to the latter a stepby-ste rotary motion, a crank-shaft geared to sai intermediate shaft to receive semi-rotational impulses, a needle-gate connected tobe vibrated by said crank, a reciprocating needle-bar mounted in said needle-gate, a feed-shaft" geared to said intermediate shaft to receive step-by-step rota'rymotion, a feedwheel actuated bysaid feed-shaft, and a travelling work-holder actuated by said feed-Wheel. v

3. In a sewing machine, a frame including a-bed and overhanging bracket-arm, a sewing shaft extending lengthwise of the bracket-arm, a needle-gate carried at the free end of the bracket-arm, a vertical shaft journaled in the bracket-arm, a crank on said shaft connected to vibrate said needle-gate,

an intern'iediate vertical shaft journaled in the bracket-arm and geared to said first mentioned vertical shaft, means actuated by the sewing shaft for imparting to said intermediate shaft step-by-step rotary impulses "with periods of dwell, a feed-wheel connected to be driven by said intermediate shaft, and a travelling work-holder actuated by said feed-wheel.

4. In a sewing machine, a needle-gate, a

needle-bar mounted to reciprocate in said gate, a rotary guide head, a hollow shaft carrying said guide-head, a slide mounted on said guide-head and formed with a transverse shoulder, -a crank on said slide connected to vibrate said gate, a slide-rod mounted in said hollow shaft and havin a cam portion coacting with said shoul' er,

spring'means on said guide-heada'cting upon said slide to retain its transverse shoulder in engagement with the cam portion of said slide-rod, and cam .me'ans driven by said sewing shaft for periodically shifting said slide-rod to increase the amplitude of-vibration of said needle-bar.

In testimony whereof, name to this specification.

EDWARD IBLALLEN.

I have signed my 

